package com.wangsd.common.utils;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import org.apache.commons.lang3.StringUtils;

import java.security.MessageDigest;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.Map;

/**
 * @Author:qc
 * @Description:MD5加密工具类
 */
public class MD5Utils {

    private static final String hexDigIts[] = {"0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"};

    /**
     * MD5加密
     * @param origin 字符
     * @param charsetname 编码
     * @return
     */
    public static String MD5Encode(String origin, String charsetname){
        String resultString = null;
        try{
            resultString = new String(origin);
            MessageDigest md = MessageDigest.getInstance("MD5");
            if(null == charsetname || "".equals(charsetname)){
                resultString = byteArrayToHexString(md.digest(resultString.getBytes()));
            }else{
                resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetname)));
            }
        }catch (Exception e){
        }
        return resultString;
    }


    public static String byteArrayToHexString(byte b[]){
        StringBuffer resultSb = new StringBuffer();
        for(int i = 0; i < b.length; i++){
            resultSb.append(byteToHexString(b[i]));
        }
        return resultSb.toString();
    }

    public static String byteToHexString(byte b){
        int n = b;
        if(n < 0){
            n += 256;
        }
        int d1 = n / 16;
        int d2 = n % 16;
        return hexDigIts[d1] + hexDigIts[d2];
    }

    public static String doSign(Object request, String mchKey) throws Exception {
        String str = JSONObject.toJSONString(request);
        Map mapTypes = JSON.parseObject(str);
        String result = "";
        try {
            List<Map.Entry<String, String>> infoIds = new ArrayList<Map.Entry<String, String>>(mapTypes.entrySet());
            infoIds.sort(new Comparator<Map.Entry<String, String>>() {
                public int compare(Map.Entry<String, String> o1, Map.Entry<String, String> o2) {
                    return (o1.getKey()).compareTo(o2.getKey());
                }
            });
            // 构造签名键值对的格式
            StringBuilder sb = new StringBuilder();
            for (Map.Entry<String, String> item : infoIds) {
                if (item.getKey() != null
                        && !item.getKey().equals("sign")
                        && !item.getKey().equals("Sign")
                        && !item.getKey().equals("mchKey")
                ) {
                    String key = item.getKey();
                    String val = item.getValue();
                    if (!(val.equals("") || val == null)) {
                        sb.append(key + "=" + val + "&");
                    }
                }
            }
            result = sb.toString();
        } catch (Exception e) {
            return null;
        }
        if (StringUtils.isBlank(mchKey)) {
            throw new Exception("商户密匙不能为空");
        }
        String mySign = MD5Utils.MD5Encode(result + "key=" + mchKey, "UTF-8").toUpperCase();
        return mySign;
    }


}